The field of this invention relates to pipe cutters and bevelers, particularly portable pipe cutter and bevelers. Some prior art portable pipe cutters and bevelers are described in U.S. Pat. Nos. 2,747,274, 3,253,336, 3,431,646 and 3,807,047. Some prior art portable pipe cutters are capable of cutting pipe of various diameters.
The pipe cutters and bevelers of the prior art have several problems. One of these problems is the inability of these prior art cutters to make cuts in restricted spaces. An example of an application for a cut in a restricted space is the cutting of a typical return bend in a heat exchanger. A return bend is a 180.degree. turn in a pipe forming a U-shape. Generally, prior to the present invention, return bend cuts were made by use of power saws as opposed to a pipe cutter because there was insufficient room to use a pipe cutter. When a cut is made by a power saw, the cut is square and has to be ground to the proper bevel. The combined downtime for the sawing and beveling operations was quite lengthy and hence unsatisfactory.
One of the reasons why the prior art pipe cutters are not used to make cuts of return bends is that the feeding means for advancing the cutting tools on the prior art cutters requires significant space to operate, and in cutting return bends there is not the necessary space. Many of the prior art pipe cutters have components of the feeding means mounted in the outer periphery of the cutter. By mounting components of the tool feeding means on the outer periphery of the cutter, the ability for the cutter to work in limited space is significantly reduced. On the other hand, without these components mounted on the outer periphery of the cutter, the cutter would not operate.
Another limitation of prior art cutters arises from components of the feeding means being subject to gualling by pipe cuttings. As a pipe is cut, cuttings are made and fall from the pipe. The hardness of these cuttings vary and depend upon the hardness of the pipe. All prior art cutters are subject to having these cuttings fall and collect in the feeding means for advancing the cutting tool. Indeed, many prior art cutters have as a component of the feeding means a wheel which travels along the exterior of the pipe during cutting operations. This wheel is particularly vulnerable to being exposed to cuttings. The operator of the prior art cutters must constantly monitor the tool so as to be sure that pipe cuttings do not collect and interfere with the feeding means. Often this requires shutting down the tool and cleaning the tool prior to completing the cut. Again, this results in increase down-time and inefficient operation.
Another problem with prior art cutters concerns the adjustments which are made to the cutter in converting the cutter from cutting pipe of one size to cutting pipe of another size. Generally, significant adjustments of the cutters and the cutting tool are necessary in order to convert the cutter from cutting pipe of one size to cutting pipe of another size. These adjustments are often cumbersome and time consuming and hence inefficient.